1. Field of the Invention
The present invention relates to a printer apparatus for a heat-sensitive adhesive sheet having a heat-sensitive adhesive layer, which normally exhibits non-adhesive properties and exhibits adhesive properties when heated, formed on one side of a sheet-like base material and, more particularly, to a printer apparatus capable of holding a heat-sensitive adhesive sheet which has been subjected to a printing process and a thermal activation process in a state in which it can be easily picked up.
2. Description of the Related Art
One type of sheets applied to commodities recently is thermally activated sheets (e.g., printed media such as heat-sensitive adhesive sheets that are formed with a coat layer including a thermally activated component on a surface thereof) which are used in a wide range of fields, e.g., POS sheets for food products, distribution/delivery sheets, sheets for medical use, baggage tags, and indication sheets applied to bottles and cans.
Such a heat-sensitive adhesive sheet is configured by forming a heat-sensitive adhesive layer that normally exhibits non-adhesive properties and exhibits adhesive properties when heated and a printable surface on a bottom side and a top side of a sheet-like base material (e.g., base paper), respectively.
The heat-sensitive adhesive is mainly composed of a thermoplastic resin, a solid plasticizing agent, or the like, and it is characterized in that it is non-adhesive at the room temperature and is activated to exhibit adhesive properties when heated by a thermal activation apparatus. Normally, the activating temperature is 50 to 150° C., and the solid plasticizing agent in the heat-sensitive adhesive is melted to impart adhesive properties to the thermoplastic resin. Since the melted solid plasticizing agent is gradually crystallized after undergoing an overcooled state, the adhesive properties are maintained for a predetermined time. The sheet is used by applying it to a surface of an object such as a glass bottle while it has the adhesive properties.
Printer apparatus utilizing such heat-sensitive adhesive sheets include that proposed in “a method and apparatus for thermally activating a heat-sensitive adhesive label and a printer” disclosed in Patent Document 1 (Japanese Patent Laid-Open No. JP-A-11-79152).
With the printer apparatus, desired characters, images, and so on are printed on a printable surface of a heat-sensitive adhesive sheet by a thermal printer apparatus having a thermal head, and the heat-sensitive adhesive layer can be activated by the thermal activation apparatus after the printing.
An operation of applying an indication sheet to a glass bottle such as a bottle for liquor or medicine, a plastic container, or the like or an operation of applying a price tag or an advertising sheet may be performed after the adhesive capability of the heat-sensitive adhesive sheet is thus exhibited. Since this eliminates a need for a release sheet (liner) as that used in a common conventional adhesive label sheet, there is an advantage in that a cost reduction can be achieved. Further, since there is no need for a release sheet which becomes a waste after being used, there is merit also from the viewpoint of resource-saving and environmental problems.
However, the conventional printer apparatus has no means for holding a heat-sensitive adhesive sheet which has been subjected to a thermal activation process.
Therefore, a user of the printer apparatus may not be able to apply a heat-sensitive adhesive sheet because it drops when ejected from the printer apparatus unless the user waits for the heat-sensitive adhesive sheet to pick it up as soon as it is ejected, which has resulted in the problem of insufficient convenience and operability.
When a heat-sensitive adhesive sheet remains in the vicinity of the ejection hole of the printer apparatus after ejection, since the heat-sensitive adhesive layer cools down and solidifies again as time (e.g., several tens seconds) passes, a problem has arisen in that the heat-sensitive adhesive sheet firmly adheres to the neighborhood of the ejection hole to become unusable and in that it necessitates a troublesome cleaning operation such as peeling the sheet away.
In particular, since a heat-sensitive adhesive sheet which has been subjected to the thermal activation process in the above-described conventional printer apparatus is simply sent out by conveying means (platen roller) provided at the thermal activation device, a problem arises in that part of the heat-sensitive adhesive layer adheres to the thermal head when the conveyance with the platen roller is stopped with the trailing end of the heat-sensitive adhesive sheet remaining on the thermal head. When the heat-sensitive adhesive adheres to a surface of the thermal head for thermal activation, problems arise when a subsequent heat-sensitive adhesive sheet comes, the problems including transfer of the adhesive to the heat-sensitive adhesive layer of the subsequent heat-sensitive adhesive sheet which can smear or damage the layer or reduce the flatness of the adherend. The deposited adhesive can be altered and burned when it is kept heated by the thermal head, which has resulted in the possibility of reduction in the heating performance of the thermal head to disable sufficient thermal activation.